Khloe Kardashian's boyfriend Tristan Thompson joined the family on a night out over the weekend.

Khloe Kardashian

Khloe Kardashian

The 'Keeping Up With The Kardashians' star celebrated the Cleveland Cavaliers' win over the Los Angeles Lakers with her beau and her family Kris Jenner and Kourtney Kardashian joined in on the celebrations too.

A source told E! News: "Khloe and Tristan arrived hand-in-hand to Catch L.A. around 10 pm. They came with a group of friends, and Kris and Kourtney joined them as well ...

"They sat next to each other at dinner and were acting really sweet. He was making nice gestures to her and showing some love. He was a complete gentleman, always making sure she was OK."

Meanwhile, Khloe recently paid tribute to her "love" Tristan to mark his 26th birthday.

Captioning a photograph of the couple, she wrote on Instagram: "To the happiest of birthdays my love! To the first of many more together! May God continue to bless you in all of your days! And may we forever look at one another like this."

And Khloe previously admitted to being "in love" with Tristan.

She said at the time: "At this moment, a few days into 2017, I feel incredibly clear and probably the happiest I've been in years. It's such a great feeling that I have my happy back!

"It's from a genuine place and the most peaceful place I've been in for longer than I can even remember ... I think when you're in love you definitely feel happy and healthy too. I like that my relationship is very normal and doesn't need to be so publicised all the time.

"So much tough s**t has gone down in my family over the past year that I've removed myself from social media a bit more and focused on what's important in my life. That's not to say 2016 wasn't a good year for me because it was, but there was a lot of real s**t that happened too. If I want to be in Ohio and do nothing, then that's what I'm going to do. Life is too short and too precious to not do what makes YOU feel the happiest. (sic)"